Thermal performance of the electron transport system Complex III in seven Alabama fishes.

Management of fish populations for conservation in thermally variable systems requires an understanding of the fish's underlying physiology and responses to thermal stress. Physiological research at the organismal level provides information on the overall effects of stressors such as extreme temperature fluctuations. While experiments with whole organisms provide information as to the overall effects of temperature fluctuations, biochemical assays of thermal stress provide direct results of exposure that are both sensitive and specific. Electron transport system (ETS; Complex III) assays quantify a rate-limiting step of respiratory enzymes. Parameters that can be estimated via this approach include optimum thermal temperature (Topt ) and optimal breadth of thermal performance (Tbreadth ), which can both be related to organismal-level temperature thresholds. We exposed enzymes of seven fish species (native fish chosen to represent a typical community in Alabama streams) to temperatures in the range 11-44°C. The resultant enzymatic thermal performance curves showed that Topt , the lower temperature for enzyme optimal thermal performance (Tlow ), the upper temperature for enzyme optimal thermal performance (Tup ), and Tbreadth differed among species. Relationships between enzymatic activity and temperature for all fish followed a pattern of steadily increasing enzyme activity to Topt before gradually decreasing with increasing temperature. A comparison of our enzyme optimum and upper-temperature limit results versus published critical thermal maxima values supports that ETS Complex III assays may be useful for assessing organismal-level thermal tolerance.

An Updated Checklist of the Mosquitoes of Oklahoma Including New State Records and West Nile Virus Vectors, 2003-06.

The mosquito fauna of Oklahoma has not been evaluated since 1965 and no report has been published concerning species associated with urban areas in the state. Mosquito collections were conducted as part of the West Nile virus (WNV) surveillance program between April and November from 2003 to 2006, using standard collection methods. A total of 74,756 adults were collected in 26 urban centers in 16 counties of Oklahoma. Altogether, 40 species were recorded during this study period, bringing the total mosquito species recorded in Oklahoma to 62 species in 9 different genera and 18 subgenera. An updated checklist of Oklahoma mosquito fauna is included with a comparison to historical records. New state records include 3 species: Aedes muelleri, Anopheles perplexens, and Culex coronator. In addition to updating the checklist, 12 species of mosquitoes were tested for WNV. Pools of Culex pipiens complex represented the highest proportion testing positive for WNV (134/766, 17.5%), followed by Cx. tarsalis (13/192, 6.8%) and Aedes albopictus (5/215, 2.3%). West Nile virus-positive mosquitoes were detected earliest in June 2005 and latest in November 2004. Infected Cx. pipiens complex testing positive for WNV were more prevalent in the eastern and central areas of Oklahoma, whereas positive Cx. tarsalis were found mainly in the western areas of the state. This distinct geographical difference needs to be monitored and followed up to ensure optimal mosquito control efforts in Oklahoma communities with mosquito control capabilities.

Updated Distribution of Aedes albopictus in Oklahoma, and Implications in Arbovirus Transmission.

A series of statewide surveys were conducted in Oklahoma in the summers between 1991 and 2004 to identify the distribution of Aedes albopictus. Adult mosquitoes were identified in 63 counties, bringing the currently known distribution of Ae. albopictus in the state to 69 of 77 counties. The widespread presence of Ae. albopictus in Oklahoma has important current and future public and veterinary health implications for surveillance and control efforts.

Extensor mechanism repair failure with use of bidirectional barbed suture in total knee arthroplasty.

Total knee arthroplasty (TKA) continues to advance as innovative devices become available. #2 PDO Quill SRS (Angiotech, Reading, Pa) bidirectional barbed suture was used for 161 primary TKAs at our facility. We report on 3 separate cases of extensor mechanism repair failure after primary TKA in which a barbed suture was used for extensor mechanism closure. Before the implementation of this device, there were no reported failures in 385 primary TKAs. We recommend that surgeons who use this device for extensor mechanism repair of a medial parapatellar arthrotomy in TKA exercise caution when operating on patients with morbid obesity, diabetes, and rheumatoid arthritis. We have discontinued use of the bidirectional barbed suture until more definitive large orthopedic studies establish its efficacy and safety.

Nontraumatic, spontaneous dislocation of polyethylene tibial insert 1 year after TKA.

The authors report a case of nontraumatic, spontaneous dislocation of a polyethylene insert detected 1 year after total knee arthroplasty. The patient demonstrated initial improvement and returned to work 4 months postoperatively. At 6 months postoperatively, the patient developed pain and a clunking sensation with motion; however, he denied any traumatic precipitating events. An arthroscopic procedure revealed arthrofibrotic formations but no signs of locking mechanism failure. At 12 months postoperatively, the patient developed sudden instability, and radiographs demonstrated an anteriorly dislodged insert. Revision surgery was performed, and the insert was removed. The insert showed some signs of fatigue due to the locking mechanism. We postulated that repetitive flexion produced an anterior superior force leading to failure of the locking mechanism.

The extended-short nail system, a novel concept in the management of proximal femur fractures.

In light of recent health care reform and the aging US Medicare population, it is becoming increasingly important for orthopedic surgeons to use effective and efficient strategies for hip fracture surgery. The Extended-Short Nail System (ES nail) is a US Food and Drug Administration-approved titanium nail which is locked at the same location as the locking hole of a short intramedullary (IM) nail. The ES nail takes advantage of an "extended-short" hybrid design combining the mechanical characteristics of a long IM nail with the surgical ease of use offered with a short IM nail.

Bilateral femoral neck stress fractures in a fire academy student.

Unilateral femoral neck stress fractures are well documented in active patients; however, the risk of a subsequent contralateral stress fracture remains unknown in patients who continue to be active. This article describes a 24-year-old male fire academy student who sustained a left femoral neck stress fracture, followed approximately 11 months later by a right femoral neck stress fracture, both of which went on to completely displace. A review of the index radiographs of each hip from outside institutions revealed femoral neck stress fractures that went undiagnosed until they displaced. The patient was referred to our institution and underwent closed reduction and internal fixation using cannulated screws in both cases. A full endocrine evaluation was performed in the following weeks and proved unremarkable. Although it is difficult to extrapolate the results from 1 patient beyond the case studied, there is cause for concern in patients who remain active following femoral neck stress fractures. Our case highlights the significance of obtaining a complete and thorough medical history on physical examination and appropriately counseling patients regarding activity level. Until further research explores this possible relationship, physicians evaluating patients with a history of a stress fracture are encouraged to be vigilant of subsequent contralateral fractures and educate patients of this potentially avoidable injury.

Sequential compression device may cause peroneal nerve palsy.

This article presents 2 cases of foot drop after joint replacement surgery that presented after sequential compression device application. In both cases, intact peroneal nerve function was documented by the surgeon in the recovery room prior to sequential compression device application. We believe that excessive pressure over the superficial aspect of the peroneal nerve in conjunction with decreased pain stimulus from analgesia may have contributed to these complications. We maintain sequential compression devices are the current mechanical thromboprophylaxis of choice; however, 4 recommendations are made to minimize the chances of this potential complication. First, precise attention should be given to patients who are short statured, as these patients can be more susceptible to having a sequential compression device improperly placed over the peroneal nerve at the fibular neck. Second, we recommend different size options become more widely available to accommodate varying patient sizes such that placement of the device is ensured to be distal to the fibular neck. Third, when using sequential compression device brands that have hook and look fastener straps, the straps should not be tight on application and frequent skin checks should be made to look for signs of over-compression. Lastly, we recommend considering delaying postoperative application of the sequential compression device until resolution of sensation following spinal or epidural anesthetic.

A randomized Phase II trial of the antiangiogenic agent SU5416 in hormone-refractory prostate cancer.

PURPOSE: To assess the activity of the antiangiogenic agent and VEGFR2 inhibitor SU5416 in hormone-refractory prostate cancer. PATIENTS AND METHODS: Thirty-six chemotherapy naïve patients were randomized to treatment with SU5416 (145 mg/m(2)) and dexamethasone premedication or dexamethasone alone. Patients in the control arm could cross over to experimental therapy after progression. Prostate-specific antigen (PSA) was measured every 2 weeks, and radiological evaluation was performed every 8 weeks. In vitro assessment of SU5416 on PSA secretion was assessed in the LNCaP cell line. Baseline serum basic fibroblast growth factor and plasma vascular endothelial growth factor (VEGF) were explored as prognostic factors. RESULTS: VEGF receptor-2 expression is detectable in prostate cancer cell lines, and SU5416 inhibited in vitro PSA secretion. No effect of SU5416 on PSA secretion or time to progression is detectable in patients. VEGF and basic fibroblast growth factor were not prognostic. Headache and fatigue were the most common SU5416 toxicities, but hyperglycemia, hyponatremia, lymphopenia, infection, and adrenal suppression, all attributable to steroids and the required central line, were common. CONCLUSION: No disease modifying effects of SU5416 were detectable in this small study. Modest toxicity, an inconvenient administration schedule, and availability of other VEGFR-targeted agents support the decision to halt further evaluation of SU5416 in prostate cancer.